Updated Rates of the Most Common Neurological Disorders

An up-to-date review of the most common neurological disorders in the United States was published in the January 30th issue of Neurology [1]. Researchers reviewed nearly 500 articles published between 1990 and 2005 to determine the rates of prevalence (meaning the total number of cases of a disease in a given population at a specific time; does not convey information about risk) or incidence (meaning the rate of occurrence of new cases of a particular disease in a given population; measures the risk of a disease) for 12 neurological disorders.
The study found that in the general population, nearly one out of every 1,000 people have multiple sclerosis, about 50% higher than a comprehensive review from 1982. It is not known whether the increased prevalence reflects improvements in diagnosis or an increase in incidence.

The study estimated that 121 out of every 1,000 people suffer from migraine and just over seven out of every 1,000 have epilepsy. The prevalence of Alzheimer’s disease was also higher than the 1982 review, finding 67 out of every 1,000 elderly Americans with Alzheimer’s disease. The prevalence of Parkinson disease was nearly 10 out of every 1,000 elderly Americans.

In children, the estimated prevalence was nearly 6 out of 1,000 for autism spectrum disorder and 2.4 out of 1,000 for cerebral palsy. The data for estimated prevalence of Tourette syndrome were insufficient.

As for traumatic brain injuries, the study found 101 out of every 100,000 Americans have a traumatic brain injury each year, a 50% decrease compared to the 1982 study. The decrease likely reflects increased restrictions on hospital admission criterial and improvements in motor vehicle safety.

For diseases described by annual incidence per 100,000 people, just over 4 people have a new onset spinal cord injury every year. Nearly two out of every 100,000 people have Lou Gehrig’s disease. The study found 183 out of every 100,000 people suffer a stroke each year; most studies attributed 80% or more to ischemia (meaning a localized deficiency of blood caused by a clot obstructing arterial flow).